I build my hoods too. This is the one over my 135 gallon viv. Its built out of 1/2 sanded plywood and pine. It sets on the to of the tank and bolts to the plastic lip. Everything is organized into layers: screen, then 6 T-12 40 Watt bulbs, a layer of MDF coated with aluminium foil tape, above all that are the vent and circulation fans and the plumbing for an irrigation system I never finished. It is hinged in the back with a 72in piano hing. It works well, but it is kind of heavy to lift. All the balast and controls are in the stand below.
Hood open:
Controls:
The tank doesn't look the same anymore, but the stand and hood do. So here they are: